Device for automatically arresting the feed-motion in grinding-machines.



, F. SOHWERD. DEVICE FOR AUTOMATICALLY ARR ESTING THE FEED MOTIOA INGRINDING MACHINES.

APPLICATION FILED NOV. 18,1908.

Patented May 4, 1909.

UNKTED STAT E FRIEDRRH SCHWERI). ()l FHANKl OltT-UN llilfl-MAIN. (IERMANY.

DEVICE FOR AUTOMATICALLY To all whom it may concern- Be it known that I,FRIEDRICH SCIIWEHI), head engineer, and resident of i111 'lrutzFrankfurt 18, l ranktort-on-the-llirin, King doni of Prussia, GermanEmpire, have invented new and useful linprm'einents in l)evices forAutomatically Arresting the Feed- Motion in Grinding-Machines, oi-whicbthe following is a specification.

instead of tne devices formeriy employed for arresting the feed motionof a grinding wheel or the like. by releasing a s )ring, it has alreadybeen proposed to use a hnger which is pressed elastically against thework and, as soon as the latter has been ground to the desired extent,influences an electric contact that interrupts a quiescent current orcompletes a working current and thereby stops the feed. in onoiot these.known arrangements the finger employed consists of a pivotally mountedlong lever which lengthens considerably the movement of the feeler pinagainst the work, and thus causing the dis advantage that theunavoidable swinging motion of the work is magnified in the sameroportion so that the contacts are liable to, lie closed prematurelywhile at the same time the mounting of the lever on a rotating axis alsoresults in iiniccuracies. These defects are obviated in the subject ofthe present applicat on by replacing the said lever by a bolt capable ofrectilinear displacement in a guide, a contactpiece being fasteneddirectly on to the bolt. The swinging movement cannot undergo anyamplification and hence the highest degree of accuracy is at-- tainedwith this device. of this kind are also attended with the defectthat theonly way to adjust the contacts is by means ofa standard piece. of workor a term lot, which has to be clamped between the eeler pin and thegrinding wheel. (onsequently it is impossible to grind any given pieceof work to any desired predetermined size. This possibility is ailordedwi h the subject of the invention, inasmuch as the distance between thecontacts can be adjusted with precision on the device itself, by meansof micrometer screws, which carry the contacts and are fitted withgradiiated heads. This adjusting device can be applied both to the firstcontact, which influences the feed movement, and to the second contact,which sto s the machine altogether.

he drawing illustrates a typical example Specification of LettersIatent.

Application filed November 18, 1908.

The. known devices ARBESTING THE FEED-MOTION IN GRINDING- MACHINES.

Patented May 4, 1909.

Serial No. 463,287.

of a device of this kind as a lateral elevation in partial section.

The bolt 1 is pressed by the spring 2 so that its outer terminal surfacepresses in a radial direction against the work. The sliding collar 3 isrigidly connected to the bolt 1 and moves in the bearing 4. At its otherend tho holt 1 carries the how 5 which surrounds the two contact devicesand is provided with a micrometer screw 8, together with the graduatedhead i] and pointer 10. By means of a small lever 11, which is supportedagainst a nut 12 serving to tighten up the spring '2, the bolt can bedrawn back from contact with the work. The whole device. is mounted on aslide-rest 14, '15 which gives a motion parallel to and at right angleswith the. work.

At the commencement of grinding, the device may be set by the aid of thegraduated head 9 and pointer 10, so as to give the interval S corres)onding to the desired coarse grinding, whi e the interval 5,corresponding to the desired iine grinding, can be set, if nec essary,by means of the graduated head 13. In the course of grinding, as soon asthe bolt 1 has traversed the adjusted distances successively, in aradial direction, and the work has consequently attained the desireddimensions after the coarse and iine grinding, the contacts 6, 7 touchone another and thus stop the feed motion of the grinding wheel.

Now what i claim and desire to secure by Letters Patent is thefollowing: 7

i. In a device for automatically arresting a feed motion, thecombination of a longitudinally movable bolt; a spring for normallyholding said bolt in contact with the work; a micrometer screw;connections between said screw and said bolt; and an electrical contactadapted to be controlled by said )ring through said connections,substantially as (lGSLI'ilJPLl.

2. in a device for automatically arresting a feed motion, thecombination ol a longitudinally movable bolt; a spring for normallyholding said bolt in contact with the work; a micrometer screw, the axisof which is longitudinally adjustable; (wnrncctions betwi-cn said screwand said bolt; and an electrical contact, one member of which is rigidwith said axis, ada )ted to be controlled by said spring through saidconnections and independentl v through the adjustment of said screw,substantially as described.

3. In a device for automatically arresting feed motions, the combinationof -a longitudinally movable bolt; a spring normally controlling thesame; a nncron'ieter screw connected to said bolt; means for adjustingsaid 3 bolt longitudinally; an electrical contact controlled by saidscrew and adapted to be closed by said spring; and means permitting saidbolt to be moved transversely, substantially as described.

4. In a device for automatically arresting feed motions, the combinationof a longitudinally movable bolt; a spring normally controlling thesame; means for adjustingthe tension of said spring; a micrometer screwconnected to said bolt; means for adjusting said bolt longitudinally; anelectrical contact controlled by said screw, one member of said contactbeing carried by said screw; said contact adapted to be closed by saidspring, and independently closed by said screw; and means permittingsaid bolt to be moved transversely, substantially as described.

5. In a device for automatically arresting feed motions, the combinationof a bolt; a spring controlling the motion thereof; a milcrometer screw;connections between said bolt and screw; an electrical contact adapted 1to be closed by said spring; a second electrical contact; and a secondmicrometer screw controlling the same, substantially as described.

6. In a device for automatically arresting feed motions, the combinationof a bolt; a spring for moving the same longitudinally; means to adjustthe tension of said spring; a micrometer screw; connections between I Ii i l FRIEDRICH SOHWERD.

Witnesses CARL Wninn, EMMA MARX.

said bolt and said screw; a second Inicro-

